[Bug]: The Milvus Java SDK occasionally returns a null object when calling MilvusClientV2Pool.getClient("MME"), even if there are many available connections in the pool, the NullPointerException will still happen.

[xiaojunxiang2023]

Is there an existing issue for this?

• [X] I have searched the existing issues

Environment

Milvus Server: 2.4.11
Milvus sdk: java-sdk 2.4.3

Current Behavior

The Milvus Java SDK occasionally returns a null object when calling MilvusClientV2Pool.getClient("MME"), even if there are many available connections in the pool, the NullPointerException will still happen.

• Client Code:

  1. PoolConfig( ):

  2. getClient( ):

• Log:

1. ActiveClient is 6, IdleClient is 0, less than the TotalPerKey(50)

2. When request 1 is stuck during client.createCollection, and request 2 comes in and executes MilvusClientV2Pool.getClient("MME"), it receives a null object.

• This is just one example; sometimes, even when request 1 is not stuck, a NullPointerException still occurs. It happens roughly once every two weeks, and the root cause remains unknown.

Expected Behavior

In situations where the connection pool is not full, it should not return a null object.

Steps To Reproduce

No response

Milvus Log

No response

Anything else?

No response

[yanliang567]

/assign @yhmo /unassign

[xiaofan-luan]

I don't think it make sense to return null to user.

when get connect and no available connections, we should just block and wait for a valid connection.

Anyone interested in this?